The present invention relates to a method and apparatus for preventing ice from forming at a roof drain and for preventing the build-up of ice and/or snow in the region of a roof drain which, in turn, assures flow of water accumulating on the roof, down the drain. This is accomplished by affixing a partially perforated waterproof container within which salt is packed, on the surface of the roof such that water flowing down the roof is drawn into the salt and subsequently gravity discharged onto the roof, flowing toward the roof drain and downspout system, mixing with water, snow and/or ice in the region of the roof drain to melt the snow and ice and thereby prevent the build up of ice at or over the roof drain which would, in turn, result in blockage of the roof drain.
The Roof Drain De-icer Apparatus is a gravity-fed, ice melting system designed to prevent the formation of ice dams at the lower part of flat and/or inclined roofs and ice build-up and water accumulation in the roof drainage system. Ice dams are a cumulative build-up of ice at the gutter and roof drain areas of roofs, which form as a result of the daily thawing and re-freezing of the snow and ice on the roof surface. Accumulation of ice in the region of the roof drain blocks the runoff of melted water off the roof, which makes the ice dam situation more problematic. When the roof drain is blocked with ice or frozen water, the down spouts, gutters and drain box fill up with water which expands when the water freezes causing damage to the roof and the drainage system and the components thereof. Installation of a Roof Drain De-icer system of the present invention prevents this damage. The Roof Drain De-icer apparatus becomes non-operational when the water or snow on the surface of the roof upstream of the De-icer Apparatus freezes.
Means for de-icing or for preventing the formation of ice on the surface of a flat, sloped roof and in the roof drainage system through which water flows, is described in the prior art. However, such teachings are clearly distinguishable from the present invention.
The Park U.S. Pat. No. 133,247 utilizes alum and salt to saturate the roof sheeting and to also saturate the felt roofing paper. Several layers of felt roofing paper saturated with alum and salt, as well as a layer of dry salt and resin and tallow are installed prior to the installation of the roof tiles. In Park, the layer of dry salt as well as the felt roofing paper and the sheeting saturated with alum and salt do not draw water from the surface of the roof and is distinguishable from the present invention. Also, replacement of the alum and salt requires removal of the roof tiles, which is highly impractical.
The Anderson U.S. Pat. No. 4,041,656 discloses a device for draining melting snow. Noting FIGS. 1 through 5, Anderson provides a collection tube 12 open at each end and provided with an inner-tubular portion 24 telescopingly received within tubular portion 14 to change the overall length. A screen 40 is provided within the collection tube 12 and is filled with salt. Screen 50 has an end portion 49 which maintains the salt within the screen. Gutter members 7 and 80 are arranged to form a V shape for directing water to the upper open end of the device. The water passes into and through the device beneath the screen but remains in a liquid state. The water runs outwardly from the lower end of the device. Anderson describes that when the water freezes to ice it reaches screen 50, causing the salt to melt the ice during the following day when melting again occurs and water runs over the ice formed in the tube causing the ice to melt. There is no teaching of water or melting snow flowing down a roof surface to a salt reservoir, which draws water into the salt to produce a saline solution within the reservoir and gravity flow of the saline solution from the reservoir onto the surface of the roof to mix with and melt snow and/or ice, preventing blockage of the drainage system as disclosed in the present invention.
The Guth U.S. Pat. No. 3,771,188 discloses a portable device having electric heating tiles 4 and 18 as well as a device for dispensing xe2x80x9ca melting aidxe2x80x9d. The Guth device is held above a region where ice is formed and cord 8 is pulled in a direction shown by an arrow in FIG. 2 to open gate 14 and dispense the material. Although Guth describes the invention as being usable on a roof of a building, the structure is intended to be manually operated, the material is dispensed to melt ice and there is no teaching of drawing snow, ice or water into a salt-filled enclosure and subsequent production and release of a saline solution from within the enclosure onto the roof.
The present invention provides a novel method and apparatus for de-icing a roof drain. The invention, in one preferred embodiment, comprises a container fabricated of a sleeve of waterproof material defining a hollow interior space. Portions of the upper and lower surfaces of the container are perforated with small holes. Rock salt, common salt or other stable, solid material capable of melting snow and ice, is packed in the annular space of the container. The free ends of the container are affixed to the surface of the roof adjacent to the roof drain with the perforated surface portions of the container being arranged in contact with the roof surface in the upstream direction relative to the flow of water toward the roof drain. The lower surface of the container engages the surface of the roof.
Water, snow or ice in the region of the upper and/or lower perforated regions are drawn into the container by the salt, forming a saline solution. Salt within the container dissolves into the water, which subsequently drains out from the perforations as a saline solution which flows along the roof toward the roof drain preventing formation of ice downstream of the de-icing apparatus and in the region of the roof drain. The saline solution combines and mixes with water in the region between the De-icer and roof drain to facilitate melting and/or prevent freezing.
Ice build up in roof drainage systems and especially roof drains causes ice and melting snow on the roof to block the flow of water, causing the roof drain to overflow, resulting in possible deterioration and structural damage to the roof and the building structure therebeneath. Also, accumulated water in the roof drain freezes, causing damage to the gutter, downspout and roof drainage system.
It is therefore one object of the invention to provide a novel method and apparatus for maintaining the roof drain free of ice and prevent ice and water build-up in the roof drain system and on the roof.
Another object of the present invention is to maintain the surface of the roof, downstream of the de-icing apparatus, free of ice.
Still another object of the present invention is to provide a novel roof de-icer apparatus in broken-down, compact kit form and which is easy to assemble and put into use.